Drill bit



June 1943- G. G. HARRVINIGTON EIAL 2,321,484

DRILL BIT Filed March 4, 1940 :s sheets-sheet 1 G. :"qgl'vn. T. H. S a cliff. C H

J1me 1943- G.-

HARRINGTON r 2,321,484

DRILL BIT s Shets-Sheed 3 Filed March 4, 1940 1'. H. stanclfif; c'. H. 8/40". mvEmoRs.

Patented-Julie .;8,- 1943 I fumes STAT-ES. PATENT' OFFICE mum. nrr

1 poration of Texas I George G. Harrington, Thomas H. Stancliif, and Clarence H. Black, Houston, Tex, assignors to s 7 Reed Roller Bit Company, Houston, Tex., a cor- Application March 4, 1940, Serial No. 322,052

16 Claims. (Cl. 255-71) Thisjinvent onrelates generally to deep well drill'bits and particularlyto cross roller bits. It hasiorits general objeeftfthe provision of a bit which will cheaper' to 'inanufacture and more durableand 'eiiici' 'nt n'service. than those here- W Q 'QF P W -J 'A specif c object of thinvention is to provide a new land'irnroved 'assembly of cutters and bearings therefo and iriechanical construction nd" that thebit will embody v an th iollowiii description and the ac-' coiripanying rawings wherein is illustrated a preferred enibodiin' nt f this invention.

s v line 3-3 of Fig. 2.

- g" 'f cross-section of the entire bit-;ta.keh along the side cutter axes thereof.

iFi'gk is'a ve1 tical cross-section of the bit-taken substantially aIong thelcross-cutter axes thereof. 5 "g 6 is a fio' 'oritat cross-section of said bit takenong the lineit tof Fig. 4. -Eigfifi is anziwi similar to the lowerportion of Fig but'sliowir'imaslightly modified form of side cu'tterrbearin'g; construction Figs: 8;:a'r'i' 29K rbisideielevations of the respect'iver'segmentsmfe the' rdrill body which carry the bearingssha ftstdf thecross cutters.

maisza View similarato the lower portion of Fig 8zdii'oEigedizsbut illustrating one of the segmeritssmhiehmpmvideseithe bearing support for onapihtheisidezcutters; 'a-zliiecilQAaissa sidemleyation of a bushing formiugi-pa. ofithe sidecutterabearm asiclaieleration of t e atiati n-iterat n arden -oi t s invention- Fig. 12 is a view in longitudinal cross section ing bushing and bridge within one of the side cutters.

As shown in Fig. 1, the bit head body isformed of four parts or segments. These are indicated in Figs. 8, 9 and 10 by the numerals I, 2 and 3, respectively. There are one each of the segments I and 2, and two of the segments 3. Each of these four segments has an upper portion adapted to form one-fourth of the shank of the bit head. These are adapted to fit together and have beveled portions adjacent their outer surfaces as indicated at 4 and. 5, for the purpose of welding the parts together, as will be hereinafter described.

.The segment I, at its lower end, has a downwardly and inwardly extending bearing supporting shaft 6, with a pair ofroller bearing races 1 I and 8 thereon, and a thrust 'ball bearing race 9 between the two. Toward its free end this shaft is also supplied with a friction bearing surface Ill. The segment 2 is provided with a downwardly and inwardly extending shaft ii at its lower end, the-same being provided with roller races l2 and 1 l3, with a ball thrust race ll between them. The segment 3, atits lower end, is provided with a short downwardly and inwardly extending bearing support comprising an axially extending annular flange i5 and has a passage therethrough axially of said support, as shown at IS in Fig. 4. Extending into the opening iii of each of the segments 3 is a bearing bushing "having an 'outer extension l8 for that purpose. This extension 18 is secured in place by welding Is.

The bushing i1 isprovided with a radial flange 20, which abuts the end of the bearing support l5 and extends outwardly to provide a ball bearing race 2i. This flange is wider at its outer periphery so as to form an overhanging part 22 and provide sufficient width for the ball race 2|. This bushing is also provided with an inner extension 23 adapted to provide a roller race. It is noted that this roller race partly underlies the overhanging portion 22 of the flange, thus making for a longer and stronger effective side cutter bearing without increasing the overall length bridge conillustrating the manner of assembling the bearthereof. This construction also provides a tortuous path through the hearing as a wholeand retards flow of the gritty and destructive drilling mud therethrough. In order" to further hinder any tendency of mud to flow through the hearing, a sealing ring 22a is carried on the overhanging part 22 of the flange and isin contact with the adjacent inner wall of the cutter. Extending between the inner ends of the bushings I1 is i a bridge 24 having sockets therein to receive the inner ends 25 and 26 of the shafts 6 and Ii,

respectively, which substantially meet each other in the form shown and having projecting end portions 21 extending outwardly through the bushings I1 and held in place by the same welding [9 that holds said bushings.

Each of the bushings I! has its flange bored adjacent the upper side thereof in a substantially axial direction to provide a channel through which balls may be inserted into the ball races 2!. These channels are then closed by means of plugs 28 and when the bushings are in place within the segments 3, the plugs 28 will be held in place by contact with the bearing supporting portions iii of the segments 3.

In a slight modification illustrated in Fig. 7, the bushing i1 is not provided with the inner extension 23, but instead, the bridge 24' is provided with an enlargement 23' which forms the roller bearing race provided in the other modification by the extension 23. In all other respects the two forms are identical, and it will be noted that in this form also the inner roller race 23' underlies the overhanging part of the flange.

After the bit has been assembled and the segments welded together, the outer surface of the shank thereof is threaded as shown at 29, and there is inserted into the inner portion thereof a slush nozzle assembly 30, having openings 3| and 32 at its lower end for the distribution of slush to the respective cutters of the bit. This 1 tube is formed with a flange 33 at its upper end and adapted to seat within the upper end of the shank against a sealing ring 34 provided for the purpose of preventing leakage of slush between the tube and the interior of the bit shank.

The tube is held in place by means of a snap ring 35 inserted in a slot 36 in the upper inner wall of this shank above the flange 33. The flange 33 on one side is provided with a lateral extension 31 forming an integral key which engages within the key way 38 in the bit head.

The cutters and bearings therefor which complete the bit illustrated by the drawings, are illustrated in Figs. 4 and 5. Mounted on the cross cutter shaft 6 is a cross roller cutter 39 having formed on its interior races for two sets of roller bearings 40 and 4| and a set of thrust ball bearings 42. These bearings cooperate with the said races within the cutter 39 and with the races 1., 9' and 9, respectively, on the shaft 3.

The cutter 39 also has its inner portion formed with an inwardly extended friction bearing surface 43 in contact with the friction bearing surface Il'l on the shaft 6.

The other cross roller cutter 44 is provided on its inner surface with races for the two sets of roller bearings 45 and 43 and a set of ball thrust bearings 41. These bearings co-operate with the said races on the roller cutter 44 and with the races i2, i3 and M. respectively on the cross cutter shaft H. I

Each of the side roller cutters 48 has the major portion of its length formed with a relatively large inner diameter, a part of which is adapted to provide a race for the outer roller bearings 49 The bearing construction just referred. to provides a ball bearing for taking the end thrust,

upon the cutter and provides two spaced roller bearings which not only serve to take the radial load upon the cutter, but also serve to take such loads as would tend to tilt the: cutter about an axis transverse to its own axis. They thus. pro-- vide a very durable and stable bearing and by virtue of the fact that the inner rolier: hearingv 52 partly underlies the ball bearing 50),, this re.- sult is accomplished within. the cutter which is relatively short, and is short enough to lie within the available space to one side of the cross; roller cutters. I

In assembling the bit above described, the bushings I! will first be placed in the side cuttters 48, as shown in Fig. 12, and the balTs; forming the bearing 50 will be dropped into place. The plug- 28 will also be inserted Next the rollers 49 will be placed upon the part [15 of the: segment 3 and the assembled. cutter and bushing placed over these rollers. The rollers; I 2: willl then be slipped into place and the bridge 24 be assembled with respect to the two side out; ter assemblies, as shown inFig. 4.

The cutters 39 and 44 be assembled upon the parts I and 2 by first placing the respective roller and ball bearings I 4t and 42', and 45,, 43%

and 41 in place on their shafts and placing the cutters 39 and 44 over said shafts; The elements I and 2 will then be assembled. with; their inner ends fitted into the openings provided therefor in the bridge: and suitable-meanswill be placed between the upper ends of these seg-' ments to properly position said upper ends. The parts will be clamped. together with suitable clamping means and the various weldinzopeme tions performed after which the threads 2!? will be cut on the shank, and the upper portion of the bit bored to receive the nozzle assembly 34 The insertion of this nozzle assembly then the snap ring 35 for holding it in place completes the drilling bit. The result is a composite bit body formed of the segments welded together, and the lower end of each segment provides at downwardly projecting bearing extension carrying the bearings for the respective cutters-c The structure above described constitutes a means whereby a very durable and ing bit is provided, and. whereby all of the various objects and advantages sought by this: invention are attained.

Having described our invention, we clahm:

1. In a drill bit, a bit:- headi four .segi'nental sections integrally ioined together ad.-

jacent their upper ends, each at said sections having an inwardly extending bearing: supporting part, two of said substantially meeting each other and together extending across the lower portion of said bit head, a of cross roller cutters on said part; 1:,

- a bridge extending between the other two of said parts and having. openings receiving the inner ends of said'first parts, a bushing ext min each of said other two parts and at portion of each side cutter support, each of said bushings having a radial thereon: formed with a thrust bah race, said flange undercut to provide an inner roller me at smaller diameter than said thrust bali race andunxbrlying said ball race, a side cutter on each of said bushings having a cor lace each of said races on said and balls; and rollers in said races respectively for said side cutters against thrust and radial lhlds.

2. In a drill but, a bit head comprising four segmental sections integrally joined together adjacent their upperends, each of said sections ing between the inner ends of said bushings and having an inwardly extending cutter bearing supporting part, two of said parts substantially meeting each other and together extending across the lower portion of said bit head, a pair of cross roller cutters on said parts respectively, a bridge extending between the other two of said parts and having openings receiving the inner ends of said first parts, a bushing extending into each of said other two parts and providing a portion of each side cutter bearing support, each of said bushings having a radial flange thereon formed with a thrust ball race, said flange being undercut to provide an inner roller race of smaller rality of segmental sections integrally joined together adjacent their upper ends, each of said sections having an inwardly extending cutter bearing supporting part, a bushing extending into one of said parts and' providing a portion of a side cutter bearing support thereon, said bushing having a radial flange formed with a thrust ball race in its outer periphery, said'flange being undercut to provide an inner roller bearing race.

of smaller diameter than said thrust ball race and underlying said ball race, a side cutter on said bushing having a corresponding race opposite'each of said races on said bushing and balls and rollers in said races respectively for supporting said side cutter against thrust and radial loads.

4. In a drill bit having a body with downwardly projecting bearing extensions, and cutters carried thereby, a downwardly and inwardly extending cutter bearing on each of said extensions,

a portion of each of said bearings being integral with its extension and providing a roller race, each of said roller races and the portions of said extensions with'which, they are integral having a bore therethrough coaxial with the correspond ing bearing, and a portion of each of said bearings consisting of a bushing extending into said bore and having a ball thrust bearing race thereon, balls and rollers in said races, and a member extending between the inner ends of said bearings and having parts extending through said bushings, and means securing said parts and bushings rigidly to each other and to said extensions.

having parts extending through said bushings and rigidly secured to said bushings and extensions, a third portion of each of said bearings being formed on said bridge member inwardly from the inner ends of said bushings and providing a second roller bearing race and rollers and balls in said roller and ball bearing races respectively. I

. 6. In a drill bit having a body with downwardly projecting bearing extensions, and cutters carried thereby,.a downwardly and inwardly extend ing cutter bearing on each of said "extensions, a portion of each of said bearings being integral with its extension and providing a roller race,

and a porton of each of said bearings consisting of a bushing rigidly secured tosaid extension and having a radial flange with a ball thrust bearing race formed in its outer edge, said flange having an opening therein extending longitudinally with respect to the axis of said bushing from the outward and upward surface of said flange into communication ,with said ball thrust bearing race, whereby the'balls may be inserted into said race, means for plugging said opening and adapted to be held in place in said opening by contact with the adjacent portion of said extension when said bushing is in place on said extension, balls, and rollers in said races, and a member extending between the inner ends of said bearings and having partsextending through said bushings, and means securing said parts integrally to said extensions.

7. In a drill bit having a body .with a downwardly projecting side cutter bearing extension, and a side cutter carried thereby, a downwardly and inwardly extending bearing on said extension, aportion of said bearing being integral with'said extension and providing an outer roller race, and a portion of said bearing consisting of a bushng rigidly-secured to said extension andhaving a ball thrust bearing race formed in its outer periphery, the portion of said bushing supporting said ball thrust bearing race being undercut, and means'providing an inner roller race partly in said undercut portion and underlying said ball thrust bearing race, said side cutter v having a race opposed to each of said races above 5. In a drill bit having a bit head with downwardly projecting side cutter bearing extensions, and side cutters carried thereby, a side cutter bearing extending downwardly and inwardly from each of said extensions, a portion of each of said bearings being integral with said extensions respectively, and providing an outer'roller bearing race, each'of said roller races and the,por-

tions of said extensions with which they are integral having a bore therethrough coaxial with the corresponding bearing, a second portion of each of said bearings comprising a bushing ex-v tending into said bore, and formed with a thrust ball bearing race, and a bridge member extendmentioned with the race opposing said inner roller raceextending into said undercut portion, and balls and rollers in said races respectively to form inner and outer roller bearings and an in-Q termediate ball thrust bearing for said cutter.

8. In a drill bit having a bit head with a downwardly projecting side cutter bearing extension thereon and a side cutter carried thereby, a side cutter bearing extending downwardly and inwardly from the lower portion of said extension, said side cutter bearing comprising an outer roller bearing .race, an intermediate ball thrust bearing race, and an inner roller bearing race,

said outer roller bearing race and said ball thrust bearing race being of larger diameter than said inner roller bearing race, said inner roller bearing race extending outwardly beneath said ball thrust bearing race, said side roller-cutter being mounted on said bearing and having a part of larger diameter forming races for said outer roller bearing and said ball thrust bearing respectively, and a part of smaller diameter extending radially inwardly and overlying said innerroller bearing race and extending outwardly beneath said ball thrus't bearing race, and rollers and balls in said roller and ball races respectively.-

9. In a drill bit, a side cutter bearing comprisintermediate ball thrust bearing, said inner radial bearing being of smaller diameter than and hav- -ing both its inner and outer races and its rollers partly underlying said ball thrust bearing.

11. In a drill bit, a bit head having a depending arm, an integral bearing element extending downwardly and inwardly from the lower portion of said arm and having a bore therethrough, an attached bearing element, a cutter on said bearing element, cooperating ball races within said cutter and on said attached bearing element, a

passageway extending from an outwardly facing portion of said bearing element into the said bearing race thereon, balls in said race adapted to be inserted through said passageway into said race while said cutter is on said element and before said element has been secured to said head, means extending into said passageway and closing the same, said element having a part inserted into said bore and said head having a part adapted to hold said means in place when said element is in place withinsaid bore, and means securing said element within said bore.

12. In a drill bit, a side cutter bearing comprising axially spaced inner .and outer radial bearing portions, a thrust 'ball bearing between said radial bearing portions, one of said radial bearing portions being of a diameter smaller than said thrust ball bearing and having opposed bearing surfaces both lying partly within said thrust ball bearing.

13. In a drill bit, a side cutter bearing comprising axially spaced inner and outer radial bearing portions, a thrust ball bearing between said radial bearing portions, one of said radial bearing portions being of a diameter smaller than said thrust ball bearing and having opposed bearing surfaces, said ball thrust bearing having ing outer and inner radial roller bearings and an a part formed with'a ball race in its peripheral surface, said'part having a portion overlying a portion of both opposed bearing surfaces of said one radial bearing.

14. In a drill bit, a side cutter bearing comprising a pairof opposed bearing surfaces of larger diameter and an axially aligned pair of opposed bearing surfaces of smaller diameter. the space between the opposed bearing surfaces of one pair communicating with the space between the opposed bearing surfaces of the dther pair to provide a path open at one end of one pair of bearing surfaces and extending therefrom through both pairs of bearing surfaces to and opening at one end of the other pair of bearing surfaces, said pair of bearing surfaces of smaller diameter partly underlying said pair of bearing surfaces of larger diameter to make said path tortuous to oppose the flow of fluid into either end of and through said path.

15. A drill bit head comprising a plurality of segmental parts divided along lines extending from one end to the other end of the head, said parts each having an inwardly extending bearing portion at its lower end and a shank portion at the upper end, means for connecting the bearing portions of said segmental parts to properly position said bearing portions with respect to each other, weld metal Joining the shank portions of the segments together while in positions determined by the connections between the bearing portions of the respective segmental parts without disturbing the correlation of the interconnected bearing portions to form a complete bit shank remote from said bearing portions while said bearing portions are so positioned, said shank formed 'of joined segmental portions having its surface threaded adjacent its upper region to provide a connection for a drill string.

16. A drill bit head comprising a plurality of segmental parts divided along lines' extending from one end to the other of the head, said parts each'having an inwardly extending bearing portion at its lower end and-a shank portion at it upper end, a bridge extending between and interconnecting the inner ends of certain of said bearing portions to correlate the same with respect to each other, means carried by said bridge for engaging the inner ends of other of said bearing portions to correlateall of said bearing portions with respect to each other, weld metal joining the shank portions of the segments together while in positions determined by the connections between the bearing portions of the respective segmental part without disturbing the correlation of the interconnected bearing portions to form a complete bit shank remote from said bearing portion while saidbearing portions are so positioned, said shank formed of joined segmental portions having its surface threaded adjacent its upper region to provide a connection for a drill string.

GEORGE G. HARRINGTON. THOMAS H. STANCLIFF. CLARENCE H. BLACK. 

